WEYMOUTH – April 15 is tax day, but it could be an even more anxiety-provoking deadline for the SouthField project at the former South Weymouth Naval Air Station.

That’s the date the master developer, Starwood Land Ventures, has given officials in Weymouth, Rockland and Abington to get behind a sweeping overhaul of the project or risk having the company walk away.

But town leaders say they may not be ready to sign off by then and that a decision that will lay out the future for potentially the largest economic engine in the region can’t be rushed.

Starwood wants the Legislature to act by the end of its formal session on July 31 on sweeping changes that would slash authority of the project’s quasi-governmental overseer, South Shore Tri-Town Development Corp., and make the three towns responsible for public services on their sections of the former base in exchange for collecting property taxes.

To make that deadline, the legislation would have to be filed by April 15, said Matthew Barry, a vice president at Starwood. If that doesn’t happen, the company will re-evaluate its position and could decide to shut down the project entirely or to try to sell its stake.

The company doesn’t technically need the towns’ endorsement, but lawmakers have said they won’t back a bill without local support.

“There’s a process that has to be respected at the State House, and we’re committed to that process,” Barry said. “We’re very hopeful we’ll make that date.”

Weymouth Mayor Susan Kay and the town council have been conducting simultaneous in-depth reviews of Starwood’s proposal and have smoothed out a number of sticking points, including tightening language guaranteeing a minimum of 900,000 square feet of commercial space in Weymouth and dropping a proposal for the town to take over a $12.5 million bond from Tri-Town.

But town officials say they’re still digging into Starwood’s assertion that the deal would be a cash windfall for the town and are having their lawyers look at it.

“I don’t know why the town is put under any deadline,” Kay said. “We have something in place right now. It isn’t working and we need to fix it. What we need to decide is, is this the way to do it?”

Council President Patrick O’Connor said he hopes the council will be able to wrap up its review and start deliberating soon.

“There has to be some sort of end to this process,” he said. “There is the real threat that this doesn’t get done on Beacon Hill because they just don’t have enough time. The clock is ticking.”

Page 2 of 2 - The council meets next on Monday and could schedule a special meeting the following Monday – one day ahead of Starwood’s deadline.

Starwood has also said it could walk away from the project if the state calls in the debt on a loan to Tri-Town, which the Executive Office of Administration and Finance said it would do last month if Tri-Town doesn’t provide updated financial projections. The deadline to submit that data was Friday.

Abington Town Manager Rick LaFond said his town may wait even longer to weigh in. He said the selectmen are considering putting an article on the June town meeting warrant to see if residents will back a resolution to support some compromise legislation.

“I certainly don’t think you’re going to get a vote by the board of selectmen by the 15th,” he said. “I would be very surprised.”

Tri-Town and Rockland Selectmen Chairman Edward Kimball have released alternative proposals to revamp the project. So far, those have generated far less attention than Starwood’s.

Plans for SouthField include about 2,800 homes and apartments and between 900,000 and 2 million square feet of commercial space. About 500 people live there now, but the long-awaited commercial boom hasn’t materialized.

As master developer, Starwood owns the undeveloped land and is responsible for selling off pieces to suitable residential and commercial builders.

Starwood and Tri-Town have blamed each other for bringing the project to the brink of stagnation.

Tri-Town CEO Kevin Donovan said Starwood’s deadline may be unrealistic.

“This is all being dictated by Starwood,” he said. “We’re here to protect the public’s interest. I don’t think we should be forced or rushed to make a decision that’s going to have an impact on people’s lives.”

Christian Schiavone may be reached at cschiavone@ledger.com or follow him on Twitter @CSchiavo_Ledger.